A few days sometimes turns into a few months, then a few years LOL. Wrap the feet in wet paper towels, tuck his head under a wing or along the back, put it a freezer zip lock and get as much air out as possible. Then put it inside another freezer zip lock and squeeze all the air out of that one. Oh and don't forget to label it with species, sex and date killed

Been mounting birds for 25 yrs I've seen a lot of mistakenly packaged birds ruined because of frezzer burn , so here is my surefire way they'll keep for a long time ....Wrap the feet and head with soaked paper towels, tuck the head under the wing and vacuum pack it ..... Get All the air out you can .....whom ever told you vacuum packing the bird ruins the feathers has no idea what he's talking about ..... If you pack it right they'll keep for 10 yrs and longer ... Or if you don't have a vacuum packer .... find somthing big enough to freeze the bird in a solid block of ice ....that will keep for even longer ....Frezzer burn is what ruins unprotected frozen birds .... Ruins the feet , eyelids and head skin ...making them nearly impossible to skin out ...... Just my 2 cents ...

I would say you are fine to get it mounted. The key as others have stated is wrapping them well prior to freezing. I have found that putting the bird in 3 ziploc bags has worked very well, and has held up for years.